Coconut product and process therefor



I 'COCONUT-PRODUCTAND PROCESS THEREFOR Charles B. de Maya, Allendale,and Adolph A. Winston, Hillside, N. 1., assignors to General FoodsCorporation,

.New YorlgN. Y., a corporation of Delaware No Drawing. Application June15, 1953, 'SerialNo. 361,824

Claims. (Cl. 99-425) This invention relates to a new coconut producthaving greatly improved storagecharacteristics and to a process forproviding such a product.

The yellowing of coconut during storage is a major problem. Apparently,such yellowing is due to a reaction which takes place between the aminoacids and reducing sugars contained in the coconut. The rate ofyellowing seems to depend on the maturity of the coconut, thetemperature of its storage, and the like, and although the lapse of timewithin which yellowing begins varies, it probably starts When thecoconut is severed from the tree.

rates PatentO The ordinary productof commerce which has been shreddedand dried as soon as possible after harvesting begins to yellow 1-3months later under usual conditions.

Heretofore S02 gas has been used in the fumigation of copra for'thepurpose of preventing insect and bacterial spoilage, and it has beennoticed that at the high S02 level required for such fumigation,yellowing is forestalled.

But the resulting S02 residuals are too high to be used in foodproducts, being of the order of several thousand parts per million andnot only raisingtoxicity problems, but also imparting ofiE-fiavors tothe product. I

By S02 residual as used herein is meant the amount of sulfur-containingcompound or compounds in the product as determined by the gravimetricMonier-Williams method for S02 described in the A. O. A. C. VII, 27-5l,p. 471, September 15, 1951, which is accurate to about parts per millionat low levels. If a coconut product contains more than about 250 partsper million of S02 residual, it is unacceptable because of off-flavor."Some people can regularly detect S02 residuals in coconut prod- .ucts atlevels as low as 150 parts per million, and it is therefore preferredthat products which are .to be distributed to the general public have aresidual at the time of eating of well below about 100 parts per millionltnhas now been discovered that a coconut product highly resistant toyellowing or browning can bexobtained by contacting the meat of theinner surface .portionio'f the coconut endosperm with an aqueoussolution of sulfur dioxide, although said product is formed from theentire meat of the endosperm and its S02 content is only a fraction ofthat heretofore believed to be required for the same degree ofprotection; This may be accomplished in various ways. For example, it isknown to scrape or shred coconut meat by means ofdevices inserted intothe nut halves and engaging the inner surface of the meat; see U. S.Patent No. 2,633,883. Thus it is possible .to separate the inner surfaceportion of the meat from .the remainder for separate treatment with S02and then to vadd this treated portion of the meat to the untreatedremainder.

Thersame result can be accomplished more. conventhe desired materialcontaining sulfur dioxide, the inside 1 surface only being treated inthis case. It is more con- 2,783,152 Patented Feb. 26,"

venieut, however, to break the nuts into somewhat smaller pieces;although this procedure may resul't'in increased .502 uptake due to theadditional meat surfaces exposed to the solution, still the ratio ofsurface areato volume is quite small as compared with shredded coconutand like products.

The SOs-bearing material used to treat the nuts must be edible, i. e.,non-toxic in the amounts used, and also compatible with the coconut, i.e., it must not impart objectionable oft-flavors thereto. Subject tothese limitations any of various materials can be used, sometimes in dryform as a powder, dust,v or the like, but more often and preferably inthe form of an aqueous solution at either alkaline or .acidic'pI-Is.Examples are sulfurous acid solution; solutions of alkali (includingammonium) salts of sulfurous acid, either partially or fullyneutralized, such as sodium bisulfite and sodium sulfite; and themolecularly dehydrated pyrosulfites and metabisulfites such as sodiummetabisulfite and potassium metabisulfite. Such compounds permit the useof a pH range of the treating solution within the range of about 2.5-9,but since relatively dilute'solutions are used in practice the usual pHrange will be much narrower. It will be understood that these specificcompounds are only by way of example.

:For convenience and because it is preferred sodium metabisulfite isreferred to'particularly in the following more detailed description. itis necessary to contact the coconut meat with sodium nietabisulfite fora relatively short period of time only. Thepreferred manner of treatment.is to immerse or dip the meat in a solution Ofllhfi metabisulfite,althoughthe same effects can be achieved .-ing a dust of sodiummeta'bisulfite on a moist coconut meat surface or simply placing atablet of sodium'meta- .bisulfite in the coconut milk before the coconutis cracked. The dipping method is preferred because it is inexpensiveand convenient and its results are most reproducible.

The concentration of the SGz-containing material in the solution and thelength of time the coconut :meat remains in contact with the solutiongovern the whiteness retention of the coconut or protection againstyellowing. If the concentration is too low, the contact timesrequired-to effect thedesired protection are excessive, and in the caseof dipping procedures watersolubfle materials inthe coconutmay beleached out; On the other hand, if the concentration is .too high, thecorresponding contact time T is too short to permit adequate control.Inthe case of sodium .metabisulfite, saturated solutions can. beemployed but are not practical because of the extreme difficulty withcontroLAas well as the possibility of odor and the general wastefulnessof the material. .For. practical purposes, therefore, a range ofconcentrations of about ous solutions used for contact by dipping,..thepreferred range being about 0.251.-0%. Other SOz-contai'ning materialssuch as those mentioned above-may be 'used in amounts capable ofproviding equivalent S02 concentrations, having in mind the variationsin molecular weight between H2803, NaI-ISO3, NE12SO3, etc.

Preferably the dipping time should be at least 1 minute, since lack ofuniformity in the final product is likely to occur with very shortperiods. In order to provide the maximum amount of protection againstyellowing with the final product having an acceptably low S02 content,the concentration of sodium metabisulfite required for a dipping time of1 minute is about 3%. Similar results can be obtained using a 1%concentration and a dipping time of about 2 minutes; a 0.5%concentration-and a dipping time of about '5 minutes; ,a0.3,-%concentration and ;a-dipping time of about '10 minutes; and 0.1%concerttration and a dipping time of 30 minutes. T he S02 residtialcontained in the coconut after dipping at the con centrations and forthe periods of time just specified followed by thorough washing toremove excess S02 amounts to onlyabout 100 parts per million by weight.Moreover, after shredding and desiccating to a moisture conytentof about2-5%, the S02 residual falls to about 50 parts per million, and aftertransportation 'or storage for as long as three months to about 30 partsper million. This S02 residual is, of course, still further reduced bythe processing involved in sugaring and remoistening the coconut for thepreparation of various consumer packs.

Nevertheless the product treated in accordance with the presentinvention is protected against yellowing for as much as a year afterleaving the dcsiccating plant. Withoutsuch treatment, on the other hand,the coconut is readily susceptible to yellowing, as much as one-third ofany given lot being unacceptable within three months after leaving thedesiccating plant and most of the remainder becoming yellow within sixmonths.

It will the evident that if changed conditions should require greater orlesser protection against yellowing, corresponding changes can be madewith respect to the concentration of the dipping solution and/or thetime employed for dipping. Generally, as aforementioned, the SO:residual at the time of consumption should be less than about 100 partsper million. But if the preparation of the product for final consumptionwere such as to remove a substantial amount of SOz, as by the use of ahigh temperature, a higher SO: level would be permissible in the productprior to such preparation which in turn would permit a higher SO: levelto be imparted by the SO: treatment. Also, if the time required aftersuch treatment for further processing and distribution of the productwere to be increased, the SO: content of the coconut immediately afterthe S02 treatment should be increased in order to provide the greateramount of protection needed. In exceptional cases, therefore, the S02content after washing may be as high as 500 parts per million.

After the coconut has been treated with sodium metabisulfite asdescribed above or other SOs-containing material, it has been founddesirable to wash it. It has been discovered that washing can serve toreduce the S02 content of the coconut by as much as 50-85% withoutappreciably decreasing the amount of protection against yellowingafforded by the process of the present invention. Also, washing permitsfar greater uniformity and, therefore, much better control of theprocess and the amount of treatment given the coconut. Washing may,

of course, be carried out inany conventional way as by dipping,spraying, and the like, the time required being determined by thedesirability of removing excess SO: on

the one hand, and of avoiding excessive leaching of coconut solids onthe other hand. Using water jets under a pressure of about 30 lbs. persq. in., 5 minutes washing is about optimum.

It appears that dipping the coconut in the SOs-containing solutionresults in some of the SO: becoming combined with or tightly held by thecoconut with the rest of the SO: being only loosely held or combined.The latter is that which is removed by washing but which is notresponsible to any appreciable degree for the protection againstyellowing afiorded by the process. As an example of the desirability ofwashing, whole, capped coconuts were dipped in a 0.5% solution of sodiummetabisulfite forabout 5 minutes, and half of these only were washedwith cold water jets for 5 minutes; when the can be substantiallyundivided with excellent results being obtained. It is preferred to usecapped, whole coconuts or halved coconuts because as the degree ofsubdivision increases for any given concentration of SOz-containingmaterial and time of dipping, S02 residuals likewise increase due to theincreased surface exposed to the treatment, but the amount of protectiondoes not increase materially. The amount of protection remains about thesame even when this excess S02 is washed from the coconut, and asaforementioned prolonged unnecessary washing is undesirable becauseitresults in loss of coconut solids, the loss reaching as high as 15-20%of the entire endosperm if ordinary coconut shreds are dipped andthoroughly washed. Evidently the treatment affects primarily the innersurface portion of the coconut meat since its effectiveness is notincreased by the exposure of fresh surfaces created by subdivision. Itis believed that this localization of the effect results fromconcentration of the reducing sugars of the coconut in the inner surfaceportion of the meat, probably in a very thin layer at the inside surfaceof the coconut. If, therefore, the coconut is subdivided to any greatextent, increased surface area is exposed to the treatment and increasedamounts of 502 are picked up, but no additional protection is achievedbecause the additional surface area exposed contains practically noreducing sugars and this excess residual should be removed by washingwith the increased opportunity for losses to occur. Of course, a slightdegree of subdivision or breakage is without consequence. Thus when thenuts are cut or broken into segments averaging one inch square theincrease in S0: residual after dipping does not result in excessivesolubility losses during washing; beyond this degree of subdivision,however, the losses during washing began to increase rapidly and soonbecome so large that the cost of the product removes it from thecompetitive market. The term segments, as used hereinafter and in theappended claims, is to be understood to mean sections or fragmentsformed by dividing or breaking the nut endosperm into pieces the averagesize which is not materially less than about one inch square, incontradistinction to shredded coconut and the like the total surfacearea of which is many times greater for the same amount of coconut meat.

The process, of course, may be applied to dried coconut but suchtreatment will be for specialized uses because of the additional dryingwhich would be required and the increased loss of soluble solids whichwould re sult. In addition, the process may be applied to coconut whichhas already begun to yellow in order to prevent further yellowing.

What is claimed is:

1. In the manufacture of comminuted coconut products, a process fortreating the coconut meat to inhibit subsequent discoloration thereofwhich comprises contacting the meat of the inner surface portion of thenut 'endosperm with an aqueous sulfur-dioxide-containing solution andthen forming a comminuted mixture of the treated and untreated meat ofthe nut endosperm whereby yellowing of the nut meat during subsequentcommercial storage and distribution of said mixture is substantiallyprevented.

2. The process defined in claim 1, including the step of washing thecoconut after the S02 treatment, thereby reducing the S02 residual inthe final product.

3. The process defined in claim 1, wherein said meat of the innersurface portion of the nut is separated from the remainder andseparately contacted with said aqueous solution.

4. The process defined in claim 1, wherein segments of the nut meat arecontacted with said aqueous solution.

5. The process defined in claim 4, including the step of washing thesegments after the S02 treatment, thereby reducing the S02 residual inthe final product.

6. The process defined in claim 1, wherein said aqueous solution iscontacted with the inner surface of the substantially undivided nutmeat.

7. The process defined in claim 6, wherein the substantially undividednut meats are contacted with said aqueous solution.

8. The process defined in claim 7, including the step of washing the nutmeats after the S02 treatment, thereby reducing the S02 residual in thefinal product.

9. A process as defined in claim 1, wherein coconut in the form ofsubstantially undivided nut meats and segments thereof is contacted withsodium metabisulfite in the presence of water.

10. A process as defined in claim 9, wherein the coconut meat iscontacted with a solution of sodium metabisulfite and thereafter washed.

11. A process for preparing desiccated coconut from freshly harvestedcoconut in the form of substantially undivided nut meats and segmentsthereof which comprises contacting the coconut meat with a solution ofsodium metabisulfite having a concentration of about 0.1-3.0% by weightfor about 1-30 minutes, and thereafter washing, shredding, and dryingthe meat. 7

12. A process for preparing desiccated coconut from freshly harvestedcoconut in the form of substantially undivided nut meats and segmentsthereof which com prises contacting the coconut meat with a solution ofsodium metabisulfite and thereafter washing, shredding, and drying themeat, the time of contact with and the concentration of the sodiummetabisulfite solution being such that the coconut after washing hasanS02 residual of less than about 500 parts per million.

13. A process for preparing desiccated coconut which comprisescontacting the endosperm of substantially undivided, freshly harvestedcoconut with a solution of sodium metabisulfite having a concentrationof about 0.5% by weight for about 5 minutes and thereafter washing,shredding, and drying the coconut, the S02 residual after washing beingless than about 100 parts per million.

14. Edible desiccated comminuted coconut meat pro tected againstyellowing by an S02 residual content not.

greater than 500 p. p. m. and characterized in that the major portion ofthe S02 content is concentrated in the meat of the inner surface portionof the coconut endosperm.

15. An edible coconut product in the form of dried coconut shredscontaining not more than 500 p. p. m. of S02 residual but protectedagainst yellowing by nonuniform SOz distribution obtained by treatingsubstantially only the meat of the inner surface portion of the coconutendosperm with SOz-containing material.

References Cited in the file of this patent UNITED STATES PATENTS1,612,087 Zucker Dec. 28, 1926 2,338,184 Kaufman Jan. 4, 1944 2,506,793Kalmar et al May 9, 1950 2,592,563 Hall et a1. Apr. 15, 1952 2,615,812Kaufman et al. Oct. 28, 1952 2,628,905 Antle et a1. Feb. 17, 1953

1. IN THE MANUFACTURE OF COMMINUTED COCONUT PRODUCTS, A PROCESS FORTREATING THE COCONUT MEAT TO INHIBIT SUBSEQUENT DISCOLORATION THEREOFWHICH COMPRISES CONTACTING THE MEAT OF THE INNER SURFACE PORTION OF THENUT ENDOSPERM WITH AN AQUEOUS SULFUR-DIOXIDE-CONTAINING SOLUTIN AND THENFORMING A COMMINUTED MIXTURE OF THE TREATED AND UNTREATED MEAT OF THENUT ENDOSPERM WHEREBY YELLOWING OF THE NUT MEAT DURING SUBSEQUENTCOMMERCIAL STORAGE AND DISTRIBUTION OF SAID MIXTURE IS SUBSTANTIALLYPREVENTED.